The present invention relates to a program data transmission checking apparatus suitable for use in a transmission system of program data such as that of a commercial message. Specifically, in a system in which whether a program has been transmitted is checked by using identification data that is added to transmission data, it is intended to generate identification data having no possibility of duplicated generation and add it to transmission data by generating the identification data by using data indicating the time of an encoding process and a serial number specific to an encoder used for the encoding process.
In broadcasting programs, they need to be identified. This will be explained below for the case of commercial broadcast. In commercial broadcast, commercial messages are broadcast in the midst of each program. Usually, program data of commercial messages and the like are edited, subjected to compression coding of MPEG2, for instance, and then stored in a commercial server, for instance. Those program data are read out from the server and broadcast in a desired manner according to a program transmission list.
In checking, for the purpose of charging or the like, whether a commercial message has been broadcast, specific identification data added to the commercial message is used. Therefore, identification data assigned to respective commercial messages to be handled by a certain broadcasting apparatus should be unique to the respective commercial messages. If identification data are used in a duplicated manner, the number of times of broadcast of each program cannot be recognized correctly and hence charging data becomes incorrect.
In view of the above, conventionally it is a common procedure to use automatically generated data as identification data. This is because type-in identification data produced by an operator has a considerably high risk of duplicated generation. For example, an automatic generation process is known which uses the encoding time (for instance, the encoding start time) of encoding a commercial message program. This may be done by utilizing time information of a clock that is incorporated in an encoder. That is, the time information is used as identification data and is added to program data of commercial messages, movies, etc.
In addition to a case in which program data of commercial messages are compression-coded by an encoder incorporated in a commercial server and then stored in the commercial server, there is another case in which program data are encoded by an encoder that is outside the commercial server. Therefore, there is a possibility that program data processed by different encoders are stored in the commercial server.
Where different encoders are used, commercial messages may be encoded at the same time point of the same day, which leaves a possibility that the same identification data is generated for different commercial messages.